Index: wp-includes/class-wp-admin-bar.php
===================================================================
--- wp-includes/class-wp-admin-bar.php	(revision 28250)
+++ wp-includes/class-wp-admin-bar.php	(working copy)
@@ -352,15 +352,17 @@
 		// Add browser classes.
 		// We have to do this here since admin bar shows on the front end.
 		$class = 'nojq nojs';
-		if ( $is_IE ) {
-			if ( strpos( $_SERVER['HTTP_USER_AGENT'], 'MSIE 7' ) )
-				$class .= ' ie7';
-			elseif ( strpos( $_SERVER['HTTP_USER_AGENT'], 'MSIE 8' ) )
-				$class .= ' ie8';
-			elseif ( strpos( $_SERVER['HTTP_USER_AGENT'], 'MSIE 9' ) )
-				$class .= ' ie9';
-		} elseif ( wp_is_mobile() ) {
-			$class .= ' mobile';
+		if ( is_user_logged_in() ) {
+			if ( $is_IE ) {
+				if ( strpos( $_SERVER['HTTP_USER_AGENT'], 'MSIE 7' ) )
+					$class .= ' ie7';
+				elseif ( strpos( $_SERVER['HTTP_USER_AGENT'], 'MSIE 8' ) )
+					$class .= ' ie8';
+				elseif ( strpos( $_SERVER['HTTP_USER_AGENT'], 'MSIE 9' ) )
+					$class .= ' ie9';
+			} elseif ( wp_is_mobile() ) {
+				$class .= ' mobile';
+			}
 		}
 
 		?>